American gage standard design thread ring



May 28, 1957 I. 'r. WEDIN 2,793,443

AMERICAN GAGE STANDARD D ESIGN THREAD RING Filed Sept. '7; 1954 1,43 '7': WED/N. 37 BY ATTORNEY,

Patented May 28, 1957 United States Patent Oflice 2,793,443 AMERICAN GAGE STARlEaRD DESIGN THREAD Ivar T. Wedin, Farmington Township, Mich.

Application September 7, H54, Serial No. 454,371

3 Claims. (Cl. 33-199) This invention relates to an improvement in American gage standard design thread rings, and more particularly, to a novel thread ring gage construction.

Heretofore, the American gage standard design of thread ring included merely an outer body transversely split to define a pair of free ends. These free ends were adjusted with respect to each other by a suitable screw means in an attempt to adjust the internal diameter of the thread ring, which was interiorly threaded. The disadvantage of this type of adjustment was in the irregular flexing of the separable portions of 'the ring body so as to produce something besides a perfect circle for the inment of the free end portions of the body with respect to the remainder of the body. The result was that during the gaging operation there would not be a free-rotary movement of the thread to be gag'ed, resulting in inaccuracies.

It is the primary object of the present invention to over come this defect and to provide for uniform contraction and expansion of the internal diameter of the threaded gaging element. i

It is the further object of the present invention to thereby provide a gage body having an internal central recess which is non-threaded, and within which is re movably positioned and secured an internally threaded split ring.

It is the further object of the present invention to thus etlect adjustments of the ring body in such a manner that I "the forces produced thereby 'are transmitted uniformly .over the entire perimeter of the internal thread ring, so

that changes in its diameter are effected, at the same time maintaining a perfect circle.

drawing in which: Fig. 1.is a front elevational view of the present thread ring gage, partially broken away and sectioned for illustration.

Fig.2 is an end elevational view thereof.

' 'Pig. 3 is a section on line 33 of Fig. 1, taken on an enlarged scale.

Fig. 4 is a fragmentary sectioned diagrammatic illustration of the extent of the convexity in the outer surface of the internal split thread ring.

Fig. 5 is a fragmentary perspective view of the body of the present thread ring gage, with the internal split ring removed; and

Fig. 6 is a fragmentary side elevational view of a thread plug gage, such as might be used in adjusting the internal split ring of said ring gage.

It will be understood that the above drawing illustrates merely a preferred embodiment of the invention and that other embodiments are contemplated within the scope of the claims hereinafter set forth.

Referring to the drawing, the present invention relates These and other objects will be seen from the following I specification and claims in conjunction with the appended to an improvement in the American gage standard design of thread ring. Primarily, the present thread ring includes an annular flexible body 11, which may be constructed of a flexible material such as steel, or may be constructed of a plastic substance. Said body has a central transverse circular recess 12 extending therethrough, said central recess being annular and concave in cross section, as indicated at 13 in Fig. 3, which illustrates the gage on an enlarged scale.

There is also formed through the body the transverse locking slot 14, which extends therethrough and communicates with central recess 12, to thereby define the pair of spaced ends 15 and 16. A transverse recess is formed across the said free ends 15 and 16 with its axis at right angles to locking slot 14. Nested within said slot and bridging the said free ends is the elongated sleeve 20 within the bore 18 formed in said ends, one end of which abuts the annular shoulder 19, formed in end element 16, and which also forms the bottom wall of the counterbore 17. There is provided a split adjusting screw 21, which is exterio-rly threaded at 22 for threaded adjustment within the threaded opening 23 in end element 15. Adjusting screw 21 is also internally threaded as at 24, and is adapted to threadedly receive the threaded end of the locking screw 25, whose enlarged head 26 bears against'annular shoulder 19 of end member 16.

This construction is substantially conventional and provides a screw means interconnecting the said body ends 15 and 16 for adjusting their spaced relation, in turn regulating the internal diameter of recess 12.

Adjustment is accomplished by rotating locking screw 25 with respect to the adjusting screw 21, until the dc sired width of locking slot 14 is obtained, after which the adjusting screw 21 may be further turned with respect to end element 15 for locking the screw means in the desired position of adjustment. This structure is substantially conventional.

There are also provided through body 11 a pair of spaced radial transverse adjusting slots 28, which communicate at one end with central recess 12 and at their outer ends terminate in transverse terminal holes 27 formed through body 11 to thereby increase the flexibility of said body.

Instead of providing an internal thread for body 11, as was heretofore conventional, the central recess 12 is circular in form, but in cross section is concave in shape, and is. adapted to retainingly receive therein the hardened steel split ring: 29, which is internally threaded at 30. Said ring is annular throughout its outer surface, which is convex and is adapted to be snugly and retainingly received Within central body recess 12--13 against relative lateral displacement.

In order to maintain the said ring against rotation, there is provided the radially arranged set screw 32, which extends through body 11 and into the recess 31 formed within the outer surface of thread ring 29.

Fig. 4 diagrammatically indicates the convexity as at 33 of the internal thread ring 29. For example, the dimension indicated at 33 is approximately .010 inch and which corresponds to a thread ring having a 1 inch internal diameter, for illustration. It is contemplated, of course, that this convexity would be variable inasmuch as the purpose thereof is to anchor the said ring within the body.

The internal thread ring 29 is transversely split as at 34, defining a pair of spaced ends 35 for said ring to thereby permit flexing of the ring to regulate the internal diameter thereof in accordance with any predetermined dimension to be gaged within the limits of the particular ring.

It has been found that it is preferable to place the split portion or slot 34 in ring 29 diametrically. opposite from the adjusting slot 14 in the body, and this appears to produce the most even distribution of compressive forces when the ends 15 and 16 of the. body are adjusted with respect to each other. l

Heretofore, the adjustment of the screw means did not produce uniform changes in the internal-shape of recess 12, due to bending of material of the body. The result was that the aperture 12 became egg-shaped or elliptical, and was no longer a perfect circle. 2

By introducing the present split ring 29 with internal threads 30, the compressive forces exerted by such bending of the body are transmitted over substantially the entire perimeter or outer surface of the'sa-id ring, so that the contraction thereof to the desired internal diameter leaves the said ring with a perfectly circular threaded opening at its interior.

In order to set the ring gage to the desired dimension for a particular gaging operation, a thread plug gage 35 of the correct size is selected, which gage includes the reduced diameter shank 36, which is projected down into a tapered internal bore of the handle 38, which for gripping purposes is preferably hexagonal in shape. Said tapered lock handle has a transverse drift hole 37 therethrough to permit access to the inner end of shank 36, to assist in the removal thereof as desired.

In adjusting body 11, the thread plug gage 35 is threaded into the internal thread ring 29-30 until the correct fit is obtained so that gage 35' rotates smoothly and evenly. And this is attained by effecting adjustments of the screw elements and 21.

It has been established that a greatly improved internal 2. This is accomplished without any additional structure such as a set screw or other lock.

3. This construction also permits of ease in assembly as the body is temporarily sprung open and upon insertion of the said ring in proper registry will snap back into ring retaining position.

4. Thus there is accomplished a self-lock without additional structure, simplifying assembly and reducing cost of manufacture. 7

Having described my invention, reference should now be had to the claims'which follow for determining the scope thereof.

I claim:

1. A thread ring gage comprising an annular flexible body having a central transverse circular recess and a transverse locking slot communicating therewith and extending through said body, defining a pair of spaced ends in said body, screw means interconnecting said ends for adjusting their spaced relation, in turn regulating the internal diameter of said recess,'and an interiorly threaded transversely split ring nested and retained within said central recess with its splitportion diametrically opposed from said locking slot, said centralrecess being concave in cross-section. said split ring being of external annular convex shape,.snugly fitting within said central recess and retained against relative lateral displacement.

2. Athread ring gage comprising an annular flexible body. having a central transverse circular recess and a thread ring has been provided inasmuch as tests show that the thread plug gage 35'or the object to be gaged, if of the correct size, will rotate and thread itself effortlessly and smoothly within the internal threads of ring 29.

The direction of bending of the ends 15 and 16 of body 11 is opposite from the bending produced in the ends of split ring 29. This has the effect of subtracting any error that might be produced in the outer body due to the flexing of the free ends 15 and 16 above the terminal holes 27. Therefore, the flexing of the inner ring will greatly compensate for this unavoidable dilferential. The annular convex shape of the split ring 29 and the corresponding internal concave cross-sectional shape of the central recess 13 of body 11 has several advantages.

1. There is provided a self-contained means of locking the internal ring 29 within said body against relative lon- 5O gitudinal adjustment. Once the ring is inserted in the body, it stays in place and cannot he accidentally dislodged, nor can it creep outwardly from said body.

transverse locking slot communicating therewith and extending through said body, defining a pair of spaced ends in said body, screw means interconnecting said ends for adjusting their spaced relation, in turn regulating the internal diameter of said recess, there being spaced transverse radial adjusting slots formed in said body communicating with the central recess terminating at their outer ends in transverse terminal holes through said body toincrease its flexibility, and an interiorly threaded transversely split ring'nested and retained within said central recess, withits split portion diametrically opposed from said locking slot said central recess being concave in crosssection, said split ring being of external annular convex shape, snugly fitting within said central recess and re tained against relative lateral displacement.

3. The gage of claim 1, said spaced. ends of the body being expansible to permit interchange and replacement of the said split ring.

References Cited in the file of this patent UNITED STATES PATENTS 

